Propulsion of a probe in the colon using a flexible sleeve

ABSTRACT

An endoscopic apparatus including an internal unit, adapted to be advanced into a gastrointestinal tract of a patient so as to enable inspection of the tract, an anchor unit, adapted to be held in a position outside the gastrointestinal tract and a flexible sleeve, having a proximal end fixed to the anchor and a distal end fixed to the internal unit, wherein at least a portion of the sleeve between the proximal end distal ends is held initially in a compact state at the internal unit and is arranged to feed out from the internal unit as the internal unit is advanced into the gastrointestinal tract. A method for endoscopic examination is also disclosed.

FIELD OF THE INVENTION

[0001] The present invention relates generally to propulsion of objectswithin lumens, and specifically to methods and devices for propellingmedical instruments through the colon

BACKGROUND OF THE INVENTION

[0002] The use of an endoscope for examining a body cavity is well knownin the art The diagnostic and therapeutic advantages conferred by directexamination of the gastrointestinal tract with a flexible endoscope havemade this method a standard procedure of modern medicine. One of themost common endoscopic procedures is colonoscopy, which is performed fora wide variety of purposes, including diagnosis of cancer, determinationof the source of gastrointestinal bleeding, viewing a site affected byinflammatory bowel disease, removing polyps, and reducing volvulus andintussusception.

[0003] While colonoscopy is useful and effective, it is a difficultprocedure for a physician to perform and is painful and occasionallydangerous for the patient These problems stem from the need to push andsteer the long, flexible colonoscope through the intestine by pushing itin from its proximal end, outside the body.

[0004] It would be desirable to provide a propulsion mechanism to pushor pull the endoscope forward from its distal end, inside the body. Anumber of methods and devices have been proposed for this purpose,although none has achieved clinical or commercial acceptance.

[0005] U.S. Pat. No. 4,207,872 to Meiri et al., whose disclosure isincorporated herein by reference, describes a device and method foradvancing an endoscope through a body passage utilizing multiplefluid-filled flexible protrusions distributed along an outer surface ofa sleeve containing the endoscope. Alternately increasing and decreasingthe fluid pressure within the protrusions advances the endoscope along abody passage. Each protrusion is in direct contact with an inner surfaceof the body passage and applies local contact pressure against thisrelatively small contact surface in order to propel the endoscopeforward.

[0006] U.S. Pat. No. 3,895,637 to Choy, whose disclosure is incorporatedherein by reference, describes a device able to move through a tubularorgan by sequentially inflating and deflating first and second radiallyinflatable members The inflation anchors the inflated member against alocal region of the tubular organ, while air pressure in alongitudinally inflatable communicating part of the device moves thenon-anchored part of the device longitudinally through the tubular organSufficient contact pressure of the inflated member against a relativelysmall length of the tubular organ is required in order for the device tobe able to progress through the organ U.S. Pat. No. 3,895,637 has noprovision to distribute the contact pressure over a larger area of thetissue against which it presses in order to generate longitudinalmotion.

[0007] U.S. Pat. No. 4,321,915 to Leighton et al, whose disclosure isincorporated herein by reference, describes an everting tube device forintroducing a tool into a body cavity using alternating steps ofapplying positive pressure to evert the tube and advance the tool, andapplying a vacuum to pull the everted tube away from the tool so that anoperator can retract the tool one half of the distance it advanced inthe previous step The operator using this device is required to manuallywithdraw the tool the prescribed distance during every pressure cycle inorder to avoid causing the tool to advance too far beyond the tip of theeverted tube

[0008] U.S. Pat. No. 4,403,985 to Boretos, whose disclosure isincorporated herein by reference, describes a jet-propelled device forinsertion into body passageways Pressurized fluid is passed to thedevice from outside of the body and then ejected from an orifice in thedevice in one direction in order to propel the device in the oppositedirection. The device of U.S. Pat. No. 4,403,985 thus generatespropulsion by expelling material into the body passageway

SUMMARY OF THE INVENTION

[0009] It is an object of some aspects of the present invention toprovide an improved system and method for propelling an object within alumen.

[0010] It is a further object of some aspects of the present inventionto provide an improved propulsion mechanism for advancing an endoscopewithin a body cavity of a patient for purposes of examination,diagnosis, and treatment.

[0011] In preferred embodiments of the present invention, a probecontaining an endoscopic instrument is advanced through the lowergastrointestinal tract of a patient by inflation of a flexible sleevecoupled to the probe. One end of the sleeve is anchored, typically at oradjacent to the patient's anus. As the sleeve is inflated, preferablyusing a pressurized gas, the probe is propelled forward, and the sleeveis fed out gradually between the probe and the anus. The portion of thesleeve that is inflated expands radially outward and remainssubstantially stationary relative to the intestinal wall as long as itis inflated Longitudinal motion of the sleeve relative to the wallgenerally occurs only at and adjacent to the probe itself The probe isthus advanced easily, and trauma to the gastrointestinal tract isminimized. To remove the probe, the sleeve is deflated and is used topull the probe back out through the anus.

[0012] In some preferred embodiments of the present invention, thesleeve is passed around the probe and everts as the probe advances.Preferably, the sleeve is folded over one or more resilient ringsencircling the probe, wherein the rings most preferably comprisering-shaped springs, which encircle the outer surface of the probe andare held against the probe by magnetic attraction. Inflating the sleeveadvances the probe through the colon, causing the sleeve to unfold fromthe inside out. Thus, an external portion of the sleeve opens out onlynear the probe, while the rest of the external portion stays stationary.

[0013] In other preferred embodiments of the present invention, thesleeve is stored in a compact state, typically folded or rolled up,inside or immediately adjacent to the probe. Most preferably, the foldedor rolled-up probe is stored in a recess in a proximal portion of theprobe. As the probe advances, the sleeve feeds gradually out of itsstored state and expands against the intestinal wall.

[0014] In some preferred embodiments of the present invention, the probecomprises a separate steering unit for easing over or around curves inthe gastrointestinal tract and obstructions, such as blood clots, smalldeformations and other obstacles, so that the probe can move within thepatient's body while minimizing harmful contact and friction Thesteering unit preferably works by gas or fluid pressure, most preferablyas described in Israel Patent Application 125,397, which is assigned tothe assignee of the present patent application and whose disclosure isincorporated herein by reference. Alternatively, other steering methodsknown in the art may be used.

[0015] In some preferred embodiments of the present invention, the probecomprises instruments for examination, diagnosis and treatmentPreferably, the instruments include an imaging device, most preferably aminiature video camera and light source, as are known in the art, whichare used to capture endoscopic images. Means for operating theinstruments and receiving data therefrom comprise wires, fiber-opticlines, or tubes which are coupled to the instruments and extend to anoperator or to equipment outside of the patient, which operates theinstruments and receives data therefrom. The wires, line or tubespreferably pass through the sleeve.

[0016] In preferred embodiments of the present invention, advancing theprobe through the gastrointestinal tract by way of inflating the sleevereduces or eliminates the necessity of applying mechanical force at aproximal end of the probe (outside the patient's body) to insert theprobe, as is required using conventional endoscopes The presentinvention thus reduces or eliminates the necessity of applyingconcentrated, local pressure to any part the patient's body, reduces oreliminates rubbing and friction between the unit or parts of it and thepatient's body, and avoids ejecting fluids or other materials into thebody's passageway.

[0017] There is therefore provided, in accordance with a preferredembodiment of the present invention, endoscopic apparatus which advanceswithin a lumen, including:

[0018] a probe having distal and proximal ends; and

[0019] a flexible sleeve coupled proximally to the probe, which sleeveis inflated in order to propel the probe within the lumen

[0020] Preferably, the probe includes an imaging device, which capturesimages inside the lumen.

[0021] In a preferred embodiment, the sleeve everts as the probeadvances, wherein the sleeve is passes around an outer surface of theprobe and everts over a retaining ring, which holds the sleeve againstthe outer surface of the probe Preferably, the probe includes magneticmaterial, and wherein the retaining ring includes one or more metalsprings, which are held against the probe by magnetic attraction thereto

[0022] Further preferably, an outer portion of the sleeve, which haseverted over the ring, is anchored so as to remain substantiallystationary relative to a wall of the lumen.

[0023] In another preferred embodiment, a portion of the sleeve is heldat the probe in a compact state and feeds out from the proximal end ofthe probe as the probe advances. Preferably, the probe has a recessadjacent to the proximal end thereof, which contains the sleeve in thecompact state Further preferably, the sleeve is anchored at a positionproximal to the probe so that a portion of the sleeve that has beeninflated, between the proximal position and the probe, remainssubstantially stationary relative to a wall of the lumen

[0024] Preferably, the lumen includes a passage inside the body of apatient, most preferably a portion of the gastrointestinal tract

[0025] There is also provided, in accordance with a preferred embodimentof the present invention, a method for propelling a probe within alumen, including

[0026] coupling a flexible sleeve to a proximal end of the probe; andinflating the sleeve to advance the probe through the lumen

[0027] In a preferred embodiment, the sleeve everts as the probe isadvanced, wherein coupling the sleeve includes passing the sleeve aroundan outer surface of the probe and folding the sleeve over a retainingring, which holds the sleeve against the outer surface of the probePreferably, the method includes anchoring an everted, outer portion ofthe sleeve so as to remain substantially stationary relative to a wallof the lumen.

[0028] In another preferred embodiment, coupling the sleeve includesholding a portion of the sleeve in a compact state at the proximal endof the probe, so that the sleeve feeds out from the proximal end as theprobe advances.

[0029] Preferably, the lumen includes the gastrointestinal tract of apatient.

[0030] The present invention will be more fully understood from thefollowing detailed description of the preferred embodiments thereof,taken together with the drawings, in which.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]FIG. 1 is a schematic, sectional illustration of a probe with afolded sleeve, in accordance with a preferred embodiment of the presentinvention;

[0032]FIG. 2 is a schematic, partly sectional illustration, showing theprobe of FIG. 1 and associated apparatus in operation, in accordancewith a preferred embodiment of the present invention, and

[0033]FIG. 3 is a schematic, sectional illustration of a probe with aneverting sleeve, in accordance with another preferred embodiment of thepresent invention

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENTS

[0034]FIG. 1 is a schematic, sectional illustration of an endoscopicprobe 20, in accordance with a preferred embodiment of the presentinvention. Probe 20 comprises a probe head or top 22, which ispreferably cylindrically shaped with a transparent optical window orlens 30 at its distal end The probe contains an electro-optical package28, which preferably includes a light source and miniature video camera,as are known in the art, which capture images through lens 30. A cablebundle 32 includes wires 31, which connect package 28 and an externalconsole for use in transmitting information from and to the package.

[0035] The probe further comprises a base 24, made up of a cap 34, whichreceives an covers and an internal spindle 36, flanged at its proximalend. A flexible sleeve 26 is folded into the space between the cap andthe spindle, and feeds out of a circular slot formed between the cap andthe spindle at the proximal end of the base Cable 32 preferably passesthrough a hollow bore in the center of spindle 36, as shown in thefigure.

[0036] Sleeve 26 preferably comprises a flexible, biocompatible plastic,of any suitable type known in the art, most preferably with a wallthickness between about 0 1 and 0.5 mm and an overall diameter wheninflated of about 10 mm. The plastic sleeve 26 is folded and fastenedtightly within base 24, so as to allow the sleeve to unfold and feed outevenly from the proximal to the distal end thereof The distal end of thesleeve is firmly sealed to probe 20, so the the sleeve can be inflatedwith pressurized gas or other fluid, as described further hereinbelow.

[0037] Preferably, probe 20 includes a steering unit 23, which anglesprobe head 22 relative to base 24 The steering unit is used to aid inturning the probe around curves and avoiding obstructions in thegastrointestinal tract. It is also useful in tilting head 22 so as tocapture an image of or perform a surgical procedure on an area ofinterest that is not directly in front of the probe. Most preferably,steering unit 23 comprises a group of opposing bellows 25 and 27, asdescribed in the above-mentioned Israel Patent Application 125,397,which are inflated and deflated by gas or fluid lines 33 within bundle32 in order to turn the unit Although for simplicity, only two suchbellows are shown in the figure, it will be understood that one, three,four or more bellows may actually be used Alternatively, steering unit23 may comprise other types of steering mechanisms, as are known in theendoscopic art, such as mechanisms based on pull-wires

[0038] In addition to electro-optic package 28, probe head 22 may alsocomprise suction and/or irrigation ports, sensors of various typesand/or specially adapted surgical instruments, such as biopsy forceps.These elements are known generally in the art, and are not shown in thefigures. Substantially any suitable type of tool or sensor may beadapted and included in head 22, and coupled to external apparatus byappropriate adaptation of cable 32.

[0039]FIG. 2 is a schematic, partly sectional illustration of probe 20in use for endoscopic examination of a patient's colon 40, in accordancewith a preferred embodiment of the present invention A proximal end ofsleeve 26 is fixed by a stationary anchor 50, located outside thepatient's body, to a tube 48, which is coupled to inflation and ventingapparatus 46. Cable 32 is fed through sleeve 26 and tube 48 via anair-tight coupling to a console 44.

[0040] Probe 20 is inserted into colon 40 through anus 42. Apparatus 46is then actuated, for example, by opening a valve therein coupled to aregulated, pressurized source of CO₂ or other gas. Preferably, a gaspressure in the range of 0.3 atm is used to inflate the sleeve.Alternatively, a liquid, such as sterile water, may be used to inflatethe sleeve. Inflating the sleeve propels probe 20 forward into colon 40,thus causing sleeve 26 to unfold and feed out of base 24 of the probe.The inflated portion of the sleeve typically expands radially and maycontact the wall of the colon, but there is generally only minimal or nolongitudinal motion of the sleeve against the wall Thus, rubbing andtrauma to the intestinal wall are minimized.

[0041] As probe 20 passes through the colon, steering unit 23 is used asnecessary, as described hereinabove, to turn probe head 22 at an anglerelative to base 24. The steering unit is preferably controlled viaconsole 44 to maneuver the probe around curves and obstructions in thegastrointestinal tract.

[0042] When the endoscopic examination is completed, apparatus 46 isoperated to vent sleeve 26. The pressure in the sleeve is relieved, andthe sleeve deflates. At this point probe 20 is withdrawn from colon 40,preferably by pulling on cable 32, or on deflated sleeve 26, or both.

[0043]FIG. 3 is a schematic, sectional illustration of another probe 60,with an everting sleeve 70, advancing inside colon 40, in accordancewith a preferred embodiment of the present invention Probe 60 isgenerally similar in construction and operation to probe 20, describedhereinabove, except for the operation of everting sleeve 70

[0044] A base 62 of probe 60 is preferably made of a magnetic metaland/or contains a permanent magnet Base 62 has two grooves 68, whichreceive respective magnetic metal springs 64 and 66, which have the formof resilient rings The circumference of groove 66 is preferably lessthan the circumference of groove 64, so that spring 64 is longer thanspring 66 The resilience of springs 64 and 66 and their magneticattraction to base 62 serves to retain sleeve 70 between the springs andthe base.

[0045] Before inserting probe 60 through anus 42, sleeve 70 is passedaround base 62, and springs 64 and 66 are fitted around the sleeve andinto grooves 68. Sleeve 70 is then folded outward, or everted, overspring 64. An outer portion 78 of the sleeve is drawn through thesprings and fastened to an anchor 72. A reserve portion 74 of sleeve 70is folded or rolled up and held in a position outside the patient's body(as opposed to the case of probe 20, shown in FIG. 1, in which thereserve portion of the sleeve is held in the base of the probe)

[0046] To advance probe 60 in colon 40, sleeve 70 is inflated byinflation/venting apparatus 46. Reserve portion 74 unfolds, and an innerportion 76 thereof is pulled behind the probe in a distal direction, asshown by the arrows in FIG. 3, and everts over spring 64. Portion 76,which is moving, is contained inside outer portion 78, which contactsthe wall of colon 40 and is substantially stationary. Thus, frictionwith or trauma to colon 40 are avoided. When it is time to withdrawprobe 60, sleeve 70 is vented, and inner portion 76 is pulled back, awayfrom the patient's body, thus reversing the everting action

[0047] Preferably, springs 64 and 66 press sufficiently tightly againstsleeve 70 in grooves 68, and the sleeve itself is sufficiently elastic,so as to produce a substantially air-tight seal. Thus, the gas thatpasses through reserve portion 74 to inflate the sleeve does not leakout in large quantities into colon 40. Alternatively, the space betweeninner portion 76 and outer portion 78 is inflated to advance probe 60

[0048] Although preferred embodiments are described hereinabove withreference to a device for moving an instrument package through the lowergastrointestinal tract, it will be understood that the novel principlesof the present invention may be used to move objects in other bodycavities, and may also be used to move objects in lumens and otherregions for non-medical applications, as well An example of anon-medical application includes examination within a highly corrosiveor high-temperature environment, where it is not desirable to havemoving parts of a propulsion unit exposed to the environment It is alsounderstood that while the preferred embodiments described hereinabovehave physical data leads and control leads, the propulsion unit andinstrument package can be powered by batteries and can store data and/ortransmit data by wireless communications, as is known in the art.

[0049] It will thus be appreciated that the preferred embodiments arecited herein by way of example, and the full scope of the invention islimited only by the claims.

1 Endoscopic apparatus which advances within a lumen, comprising: aprobe having distal and proximal ends; and a flexible sleeve coupledproximally to the probe, which sleeve is inflated in order to propel theprobe within the lumen. 2 Apparatus according to claim 1, wherein theprobe comprises an imaging device, which captures images inside thelumen. 3 Apparatus according to claim 1 or 2, wherein the sleeve evertsas the probe advances 4 Apparatus according to claim 3, wherein thesleeve passes around an outer surface of the probe and everts over aretaining ring, which holds the sleeve against the outer surface of theprobe. 5 Apparatus according to claim 4, wherein the probe comprisesmagnetic material, and wherein the retaining ring comprises one or moremetal springs, which are held against the probe by magnetic attractionthereto. 6 Apparatus according to claim 4, wherein an outer portion ofthe sleeve, which has everted over the ring, is anchored so as to remainsubstantially stationary relative to a wall of the lumen. 7 Apparatusaccording to claim 1 or 2, wherein a portion of the sleeve is held atthe probe in a compact state and feeds out from the proximal end of theprobe as the probe advances. 8 Apparatus according to claim 7, whereinthe probe has a recess adjacent to the proximal end thereof, whichcontains the sleeve in the compact state
 9. Apparatus according to claim7, wherein the sleeve is anchored at a position proximal to the probe sothat a portion of the sleeve that has been inflated, between theproximal position and the probe, remains substantially stationaryrelative to a wall of the lumen. 10 Apparatus according to claim 1 or 2,wherein the lumen comprises a passage inside the body of a patient. 11Apparatus according to claim 10, wherein the passage comprises a portionof the gastrointestinal tract. 12 A method for propelling a probe withina lumen, comprising, coupling a flexible sleeve to a proximal end of theprobe; and inflating the sleeve to advance the probe through the lumen.13 A method according to claim 12, wherein the sleeve everts as theprobe is advanced 14 A method according to claim 13, wherein couplingthe sleeve comprises passing the sleeve around an outer surface of theprobe and folding the sleeve over a retaining ring, which holds thesleeve against the outer surface of the probe. 15 A method according toclaim 13 or 14, and comprising anchoring an everted, outer portion ofthe sleeve so as to remain substantially stationary relative to a wallof the lumen 16 A method according to claim 12, wherein coupling thesleeve comprises holding a portion of the sleeve in a compact state atthe proximal end of the probe, so that the sleeve feeds out from theproximal end as the probe advances 17 A method according to any ofclaims 12-14, wherein the lumen comprises the gastrointestinal tract ofa patient.